Multiple integer overflows in Sbus PROM driver (drivers/sbus/char/openprom.c) for the Linux kernel 2.4.x up to 2.4.27, 2.6.x up to 2.6.7, and possibly later versions, allow local users to execute arbitrary code by specifying (1) a small buffer size to the copyin_string function or (2) a negative buffer size to the copyin function.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2004-2721
http://www.securityfocus.com/bid/10632
http://www.securiteam.com/unixfocus/5GP0515DFW.html
http://www.debian.org/security/2008/dsa-1503
http://securitytracker.com/id?1010617
http://secunia.com/advisories/29058
http://secunia.com/advisories/11981
http://archives.neohapsis.com/archives/bugtraq/2004-06/0463.html